1. Field of the Invention
The present invention pertains to a machine for depositing a product on a plane and horizontal surface, especially a machine for depositing sintered glass, known as "frit", on cathode tube cones.
2. Description of the Prior Art
Frit-depositing machines in current use comprise a rotating cone support that works with a frit applicator comprising essentially a container that ends in a nozzle at its lower part. This applicator is joined to a guiding castor which moves along the slightly conical internal periphery of the upper (flared) part of the cone. The bead of frit deposited on the flat edge of the cone (i.e., its upper front surface intended for bonding to the slab) by these machines of the prior art is uneven for the following reasons. The rotating support of the cone does not allow the cone to be positioned in such a way that its flat edge is always strictly horizontal. This means that, if horizontality is not obtained, the distance between the applicator nozzle and this flat edge can vary. Hence, the angle of incidence between the flow of frit leaving the nozzle and this flat edge is variable, and this causes corresponding variations in the thickness an/or width of the bead deposited on the flat edge. Additionally, the guiding castor follows a path with a variable distance from the surface of the flat edge, and this means that the axis of the deposited bead does not quite accurately follow the longitudinal axis of the flat edge surface. Furthermore, even if the cone is well set on its rotating support but the internal peripheral surface of the upper part of the cone is uneven or has flaws on the path of the castor, the castor itself reflects them on to the path of the deposited bead. Finally, it is difficult to adapt one and the same machine to differing sizes of cathode tubes.